Due to environmental pollution, the quality of drinking water has dropped sharply compared to the previous century. It is still necessary to have a water purifier at home. As for the quality of the filtered water? You need the corresponding tools to test. Recently Tookfun purchased a new water purifier. Therefore, a TDS test pen is needed to check the water quality. And Xiaomi’s test pen seems to have a good reputation, so I bought one.
Appearance Gallery
The packaging box is very simple. Printed with the pattern and some attributes of the detection pen.
After opening the package, it is the main body of the detection pen. The shape is also very simple, with a pure white body without any patterns.
The top of the detection pen is a semi-permeable frosted cap.
After removing the cap, you can see the head of the pen.
The thicker one is the exposed temperature sensor; the two thinner ones are the metal titanium TDS probes.
At the end of the detection pen is the battery compartment. The battery can be replaced after opening the cover. The Xiaomi detection pen uses two AG13 batteries, which I personally think is not as convenient as using AAA batteries.
Feeling of using
The use of the Xiaomi detection pen is very simple. Just put the probe into the water sample. Judge the water quality according to the numbers on the display.
I simply tested 3 water samples.
The first is tap water, with a TDS value of 192. The water quality is hard, and it is easy to produce scale in real life.
Let’s test the water filtered by the nanofiltration water purifier, the TDS value is 66. It’s okay, it’s not RO membrane after all.
Finally, take a look at a bottled mineral water with a TDS value of 36. It can be said to be relatively low.
The actual function of TDS detection pen
The lower the TDS value, the better the water quality? This we need to consider from many aspects.
First of all, let’s talk about what TDS is?
TDS refers to the total amount of various solid substances that can be dissolved in water. Unit mg/L. It mainly reflects the concentration of Ca2+, Mg2+, Na+, K+ plasma in the water. It has a good corresponding relationship with water hardness and conductivity. The smaller the TDS, the smaller the conductivity.
The quality of water depends on its water quality indicators. Good drinking water quality should meet the corresponding national water quality standards. International water standards: 0-50TDS water is safe to drink directly; 50-120TDS water is used with caution without treatment; water above 120TDS cannot be directly imported without treatment.
But TDS is only one indicator among many water quality indicators. TDS is mainly used to detect the water quality of purified water, distilled water, RO membrane (reverse osmosis membrane) water purifiers.
In addition to the TDS value, qualified drinking water must also meet the microbiological indicators (bacterial count), toxicological indicators (heavy metal ion concentration), sensory properties (color, smell, taste, visible to the naked eye), general chemical indicators and radioactive indicators. Healthy and clean drinking water must not contain pathogenic microorganisms, chemicals and radioactive substances in the water, must not endanger human health, and have good sensory properties. Therefore, to judge the quality of water, it is necessary to conduct tests from many aspects.
Factors affecting TDS pen detection:
The TDS value cannot represent the concentration of heavy metal ions.
In drinking water, the size of TDS is the sum of the concentration of metal ions in the water quality, and it is impossible to effectively distinguish the concentration of harmful heavy metal ions. As for the number of bacteria in the water, whether the concentration of organic matter is high, whether the concentration of nitrite exceeds the standard, and whether there are pesticide residues, these cannot be reflected by the size of TDS. Even if the concentration of bacteria and heavy metal ions in the water exceeds the standard, as long as the concentration of the dissolved Ca2+, Mg2+, Na+, K+ plasma in the water decreases, the TDS value will also decrease. Therefore, the TDS detection pen cannot detect highly polluted water bodies.
The increase in TDS value may be due to the increase in water temperature.
In addition, the TDS value is also affected by the temperature of the water. Under normal circumstances, when the water temperature rises, the calcium and magnesium ions in the water combine with other substances, and the conductivity increases, so the TDS value will also increase. Therefore, high-temperature water bodies cannot be detected with TDS pens.
In addition, the accuracy of the TDS value is also low for water bodies with fast flowing speeds. Therefore, the TDS pen is not suitable for testing running water.
So, doesn’t the TDS pen have any practical effect?
Of course it works! You can use the TDS pen to test the filtering effect. Whether it is ultrafiltration, microfiltration, nanofiltration, RO membrane, if the tap water is purified, the TDS value does not change, or even becomes higher. Then it is very likely that your water purifier (water purification equipment) filter element or membrane should be replaced.
There is another problem. Many people worry that long-term drinking of purified water will lack minerals. This is nothing to worry about. It is well known that the mineral content in the water is very small, so long-term drinking of purified water does not have much effect on the human body’s intake of trace elements. And the main source of daily trace elements in the human body is diet, not water. Water is mainly used to replenish moisture.
Concluding remarks
Xiaomi’s water quality TDS detection pen has high appearance and convenient detection. The screen and buttons are waterproof, and there is an automatic shutdown function to save power. In addition, the volume is also very small and easy to carry. Of course, this model has no backlight function, and reading is difficult when the light is bad. The AG13 battery used is not as easy to buy as AAA batteries. It is hoped that the launch of the second-generation product can solve the above two problems.
Where to buy？
Product link: Xiaomi TookFun Tech Store
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Hope this article helps you,
May your life get better and better.
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